Fiber reinforced elevator belt and method of manufacture

ABSTRACT

A belt for suspending and/or driving an elevator car extending longitudinally along a length of the belt. An inner belt layer formed from a first material is bonded to the plurality of tension elements at a first side of the belt. The inner belt layer forms an inner belt surface interactive with a traction sheave of an elevator system. An outer belt layer formed from a second material is bonded to the plurality of tension elements at a second side of the belt. The plurality of tension elements are located between the first side and the second side.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to belts utilized inelevator systems for suspension and/or driving of the elevator carand/or counterweight.

Conventional elevator systems use rope formed from steel wires as alifting tension load bearing member. Other systems utilize a liftingbelt formed from a number of steel cords, formed from steel wires,retained in an elastomeric jacket. The cords act as the load supportingtension member, while the elastomeric jacket holds the cords in a stableposition relative to each other, and provides a frictional load path toprovide traction for driving the belt.

More recent developments in the area of composites include the usesynthetic fibers such as carbon fiber and glass fiber to provide ahigher strength to weight ratio than steel. The fibers are firstimpregnated with thermoset resins and then cured to form rigid andbrittle composite cords that are later surrounded with an elastomer toprovide traction for the belt. Although a belt with carbon fiber andthermoset resin will provide improved strength to weight advantagescompared to steel cord belt, significant manufacturing, performance anddurability challenges exist. For example, the long curing cycle of thethermoset resin and entrapment of air voids during cure present amanufacturing challenge. Further, the rigid construction is contrary tothe desire for a flexible belt capable of many thousands of bendingcycles without brittle or fatigue failure in the field.

BRIEF DESCRIPTION OF THE INVENTION

In one embodiment, a belt for suspending and/or driving an elevator carincludes a plurality of tension elements extending longitudinally alonga length of the belt. An inner belt layer formed from a first materialis bonded to the plurality of tension elements at a first side of thebelt. The inner belt layer forms an inner belt surface interactive witha traction sheave of an elevator system. An outer belt layer formed froma second material is bonded to the plurality of tension elements at asecond side of the belt. The plurality of tension elements are locatedbetween the first side and the second side.

Additionally or alternatively, in this or other embodiments, the firstmaterial is different from the second material.

Additionally or alternatively, in this or other embodiments, the tensionelements include steel cords, carbon fiber, polymer fiber and/or glassfiber.

Additionally or alternatively, in this or other embodiments, theplurality of tension elements are at least partially enclosed in amatrix material.

Additionally or alternatively, in this or other embodiments, the innerbelt layer includes a tape including the first material.

Additionally or alternatively, in this or other embodiments, the outerbelt layer includes a tape including the second material.

Additionally or alternatively, in this or other embodiments, the innerbelt layer and/or the outer belt layer are thermally bonded to theplurality of tension elements.

Additionally or alternatively, in this or other embodiments, the firstmaterial is one of high performance polymer fibers such as highlyoriented thermoplastics (i.e. Dyneema®), aramids (i.e. Kevlar®,),aromatic polyethers (i.e. PEEK, PEKK) or polyimides to enhance abrasiveand wear resistance of the inner surface.

Additionally or alternatively, in this or other embodiments, the secondmaterial is selected to enhance one or more of moisture or UVresistance, fire resistance or vibration damping of the belt.

In another embodiment, a method of forming a belt for suspending and/ordriving an elevator car includes arranging a plurality of tensionelements to extend longitudinally along a belt length. An inner beltlayer comprising a first material is applied to a first side of theplurality of tension elements to form an inner belt surface. An outerbelt layer comprising a second material different from the firstmaterial is applied to a second side of the plurality of tensionelements forming an outer belt surface. The plurality of tensionelements are located between the inner belt surface and the outer beltsurface.

Additionally or alternatively, in this or other embodiments, theplurality of tension elements are at least partially enclosed in amatrix material prior to applying the inner layer and/or the outerlayer.

Additionally or alternatively, in this or other embodiments, the tensionelements include steel cords, carbon fiber and/or glass fiber.

Additionally or alternatively, in this or other embodiments, the innerbelt layer includes a tape including the first material.

Additionally or alternatively, in this or other embodiments, the outerbelt layer includes a tape including the second material.

Additionally or alternatively, in this or other embodiments, the innerbelt layer and/or the outer belt layer are thermally bonded to theplurality of tension elements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic of an exemplary elevator system having a 1:1roping arrangement;

FIG. 1B is a schematic of another exemplary elevator system having adifferent roping arrangement;

FIG. 1C is a schematic of another exemplary elevator system having acantilevered arrangement;

FIG. 2 is a cross-sectional view of an embodiment of an elevator belt;and

FIG. 3 is schematic view of an embodiment of a manufacturing process foran elevator belt.

The detailed description explains the invention, together withadvantages and features, by way of examples with reference to thedrawings.

DETAILED DESCRIPTION OF THE INVENTION

Shown in FIGS. 1A, 1B and 1C are schematics of exemplary tractionelevator systems 10. Features of the elevator system 10 that are notrequired for an understanding of the present invention (such as theguide rails, safeties, etc.) are not discussed herein. The elevatorsystem 10 includes an elevator car 12 operatively suspended or supportedin a hoistway 14 with one or more belts 16. The one or more belts 16interact with one or more sheaves 18 to be routed around variouscomponents of the elevator system 10. The one or more belts 16 couldalso be connected to a counterweight 22, which is used to help balancethe elevator system 10 and reduce the difference in belt tension on bothsides of the traction sheave during operation.

The sheaves 18 each have a diameter 20, which may be the same ordifferent than the diameters of the other sheaves 18 in the elevatorsystem 10. At least one of the sheaves could be a traction sheave 52.The traction sheave 52 is driven by a machine 50. Movement of drivesheave by the machine 50 drives, moves and/or propels (through traction)the one or more belts 16 that are routed around the traction sheave 52.

At least one of the sheaves 18 could be a diverter, deflector or idlersheave. Diverter, deflector or idler sheaves are not driven by a machine50, but help guide the one or more belts 16 around the variouscomponents of the elevator system 10.

In some embodiments, the elevator system 10 could use two or more belts16 for suspending and/or driving the elevator car 12. In addition, theelevator system 10 could have various configurations such that eitherboth sides of the one or more belts 16 engage the one or more sheaves 18(such as shown in the exemplary elevator systems in FIGS. 1A, 1B or 1C)or only one side of the one or more belts 16 engages the one or moresheaves 18.

FIG. 1A provides a 1:1 roping arrangement in which the one or more belts16 terminate at the car 12 and counterweight 22. FIGS. 1B and 1C providedifferent roping arrangements. Specifically, FIGS. 1B and 1C show thatthe car 12 and/or the counterweight 22 can have one or more sheaves 18thereon engaging the one or more belts 16 and the one or more belts 16can terminate elsewhere, typically at a structure within the hoistway 14(such as for a machineroomless elevator system) or within the machineroom (for elevator systems utilizing a machine room. The number ofsheaves 18 used in the arrangement determines the specific roping ratio(e.g. the 2:1 roping ratio shown in FIGS. 1B and 1C or a differentratio). FIG. 1C also provides a so-called rucksack or cantilevered typeelevator. The present invention could also be used on elevator systemsother than the exemplary types shown in FIGS. 1A, 1B and 1C.

The belts 16 are constructed to have sufficient flexibility when passingover the one or more sheaves 18 to provide low bending stresses, meetbelt life requirements and have smooth operation, while beingsufficiently strong to be capable of meeting strength requirements forsuspending and/or driving the elevator car 12.

FIG. 2 provides a schematic of an exemplary belt 16 construction ordesign. The belt 16 includes a plurality of tension elements 32extending longitudinally along the belt 16. The tension elements 32 maybe cords formed from steel wires, or may be formed from other materialssuch as carbon fiber, polymer fiber such as aramid fiber and/or glassfiber. The tension elements 32 are arrayed laterally across a width 34of the belt 16 and, as stated above, extend longitudinally along a beltlength. In some embodiments, a binder or matrix 36 is disposed aroundthe tension elements 32 to retain the tension elements 32 in selectedpositions relative to each other. In some embodiments, the matrix 36 isformed from a thermoplastic polymer such as nylon, PP (polypropylene),PET (polyethylene terephthalate), PEI (polyetherimide), or PEEK(polyether ether ketone). Fillers and/or modifiers may be added to thematrix 36 to enhance select properties of the matrix such as strength,durability, and/or frictional properties.

The belt 16 construction is a laminate construction, with the tensionelements 32 disposed at a middle portion 38 of the belt 16, in someembodiments substantially at a center of the belt 16, and layers ofadditional material disposed on the tension element 32 layer to form theremainder of the belt 16. This construction of the belt 16 allows foruse of different materials in discrete layers of the belt 16, andselection of those materials based on selected properties for thoselayers. For example, in the embodiment shown in FIG. 2, one or moreinner layers 40 forming an inner or traction surface 42 of the belt 16,are applied to the tension members 32 and are formed from materialsselected for their abrasive and wear resistance as the traction surface42 interacts with the traction sheave 52 to drive the elevator system10. Materials suitable for the inner layers 40 include performancepolymer such as highly oriented thermoplastics (i.e. Dyneema®), aramids(i.e. Kevlar®), aromatic polyethers (i.e. PEEK, PEKK) polyimides,urethanes and other abrasion resistant polymers.

In the middle portion 38 of the belt 16 a number of middle layers 44 maybe included, in addition to or instead of the tension elements 32. Themiddle layers 44 are formed form materials having high stiffness andhigh strength, especially high tensile strength. Materials utilized forthe middle layers 44 include carbon fiber. In addition, the carbon fibermaterial would utilize fine fibers to maintain high tensile stiffness ofthe middle layers 44 while having relatively low bending stiffness toprevent the belt 16 from having a high rigidity.

The belt 16 also includes one or more outer layers 46, forming an outersurface 48 opposite the traction surface 42. The outer layers 46 may beformed from the same materials as the inner layers 40, or alternativelymay be formed from other materials that are, for example, more costeffective than those of the inner layers 40, or materials having otherproperties to enhance performance of the belt 16. For example, the outerlayers 46 may be formed of materials providing environmental protectionsuch as moisture or UV resistance, or fire resistance or vibrationdamping. Materials that may be utilized for fire resistance includefiberglass mesh, Kevlar® or aluminum mesh. It is to be appreciated thatsuch environmental protection materials may also be utilized in theinner layers 40. In addition to or instead of environmental protection,the outer layers 46 may include materials or sensors 54 embedded thereinto monitor the health or condition of the tension elements 32. Thesensors 54 may periodically transmit information regarding the conditionof the tension elements 32 to a control system (not shown).

Referring now to FIG. 3, a schematic illustration of a manufacturingprocess for a belt 16 is illustrated. Each layer 40, 44, 46 is formedusing preformed tapes, with the functional material of the layer formedinto the tape with a tape matrix material. As with matrix 36, the tapematrix material may be a thermoplastic polymer such as nylon, PP, PET,PEI or PEEK. The tapes are then consolidated into the belt 16 as shownby a continuous manufacturing process. The process utilizes one or moresets of forming rollers 56 through which the tapes forming layers 40, 44and 46, along with tension members 32 are passed. The rollers 56 applypressure to the structure. To cure the belt 16 in embodiments here thetape matrix is a thermoplastic polymer, for example, the structure isthen heated to adhere the layers 40, 44, 46 to each other. In otherembodiments, adhesives or other means may be utilized to adhere thelayers 40, 44, 46 to each other.

The structure and manufacturing process of the belt 16 disclosed hereinallows for tailor of belt 16 properties to achieve a wide variety offunctional requirements, and in some embodiments allows for healthmonitoring of the belt. The materials may be selected to improvefunctional life of the belt 16. Each layer of the belt may be tailoredfor specific requirements without significant changes to themanufacturing process or to other layers of the belt. Further, thecontinuous manufacturing process reduces manufacturing cost of the belt.

While the invention has been described in detail in connection with onlya limited number of embodiments, it should be readily understood thatthe invention is not limited to such disclosed embodiments. Rather, theinvention can be modified to incorporate any number of variations,alterations, substitutions or equivalent arrangements not heretoforedescribed, but which are commensurate with the spirit and scope of theinvention. Additionally, while various embodiments of the invention havebeen described, it is to be understood that aspects of the invention mayinclude only some of the described embodiments. Accordingly, theinvention is not to be seen as limited by the foregoing description, butis only limited by the scope of the appended claims.

1. A belt for suspending and/or driving an elevator car, comprising: aplurality of tension elements extending longitudinally along a length ofthe belt; an inner belt layer formed from a first material bonded to theplurality of tension elements at a first side of the belt, the innerbelt layer forming an inner belt surface interactive with a tractionsheave of an elevator system; and an outer belt layer formed from asecond material bonded to the plurality of tension elements at a secondside of the belt, the plurality of tension elements disposed between thefirst side and the second side.
 2. The belt of claim 1, wherein thefirst material is different from the second material.
 3. The belt ofclaim 1, wherein the tension elements comprise steel cords, carbonfiber, polymer fiber and/or glass fiber.
 4. The belt of claim 1, whereinthe plurality of tension elements are at least partially enclosed in amatrix material.
 5. The belt of claim 1, wherein the inner belt layercomprises a tape including the first material.
 6. The belt of claim 1,wherein the outer belt layer comprises a tape including the secondmaterial.
 7. The belt of claim 1, wherein the inner belt layer and/orthe outer belt layer are thermally bonded to the plurality of tensionelements.
 8. The belt of claim 1, wherein the first material is one ofhigh performance polymer fibers such as highly oriented thermoplastics(i.e. Dyneema®), aramids (i.e. Kevlar®,), aromatic polyethers (i.e.PEEK, PEKK) or polyimides to enhance abrasive and wear resistance of theinner surface.
 9. The belt of claim 1, wherein the second material isselected to enhance one or more of moisture or UV resistance, fireresistance or vibration damping of the belt.
 10. A method of forming abelt for suspending and/or driving an elevator car comprising: arranginga plurality of tension elements to extend longitudinally along a beltlength; applying an inner belt layer comprising a first material to afirst side of the plurality of tension elements to form an inner beltsurface; and applying an outer belt layer comprising a second materialdifferent from the first material to a second side of the plurality oftension elements forming an outer belt surface, the plurality of tensionelements disposed between the inner belt surface and the outer beltsurface.
 11. The method of claim 10, further comprising at leastpartially enclosing the plurality of tension elements in a matrixmaterial prior to applying the inner layer and/or the outer layer. 12.The method of claim 10, wherein the tension elements comprise steelcords, carbon fiber, polymer fiber and/or glass fiber.
 13. The method ofclaim 10, wherein the tension elements comprise steel cords, carbonfiber, polymer fiber and/or glass fiber.
 14. The method of claim 10,wherein the outer belt layer comprises a tape including the secondmaterial.
 15. The method of claim 10, wherein the inner belt layerand/or the outer belt layer are thermally bonded to the plurality oftension elements.